N-acetyltransferase(NAT)is a kind of enzyme that catalyzes the transfer of acetyl group between acetyl-coA and amine.Bombyx mori,a model lepidoptera insect,is an economic insect.In this study,according to Bombyx mori NAT gene(BmNAT)registered in NCBI database(Gen Bank accession number: XP_004932777.1),bioinformatics analysis was carried out.The results showed that BmNAT contained an open reading frame(ORF)of 1065 bp nucleotides encoding 355 amino acids(aa).After prokaryotic expression,the purified BmNAT fusion protein was used to immunize a New Zealand rabbit for the preparation of polyclonal antibody.Subcellular Localization displayed that BmNAT was distributed in the cytoplasm and nucleus.The expression levels of BmNAT at different developmental stages and different tissues of the 5th instar Bombyx mori larvae were detected by Western blotting.The results displayed that BmNAT was highly expressed at moth stage,egg stage and in head of the 5th instar larvae,being very close to the determined result of transcription level of BmNAT.Flow Cytometry analysis indicated that BmNAT may have influence on the cell cycle.Finally,using site-specific mutagenesis,immunoprecipitation and western blotting,we further identified the acetylation of BmNAT itself.These results laid the foundation for better understanding of the new gene regulatory mechanism of the post-translational modification level in the silkworm,Bombyx mori.